Anti-pick lock



L. GUTMAN ANTI-PICK LOCK Nov. 14, 1961 3 SheetsSheet 1 Filed June 24, 1959 ///J.,/Wf

L. GUTMAN ANTI-PICK LOCK Nov. 14, 1961 3 Sheets-Sheet 3 Filed June 24, 1959 INVENToR, od/s GUJMA/ ATTORNEY United States Patent Office 3,0%,3l8 Patented Nov. 14, 1961 3,008,318 ANTI-PICK LOCK Louis Gutman, Fitchburg, Mass., assignor to Independent Lock Company, Fitchburg, Mass., a corporation of Massachusetts Filed June 24, 1959, Ser. No. 822,513 Claims. (Cl. 70-38) This invention relates to a pickproof lock, and more particularly to a pickproof pin tumbler lock.

Known to me is the provision in a lock assembly of a pin tumbler having means which endeavor to minimize use with an unwarranted key by the employment of an auxiliary pin or pins which come into play when an improper key is used, or which is subject to plug rotation by picking tools which progressively position the parting lines of the driver and follower pins along the plug bearing because of the tolerance clearance of the plug Within the plug casing. Such picking means rely, in a measure, upon the bolt resistance or positive pressure engagement between the cylinder plug or cam thereof with the bolt actuating mechanism. The provision in such assembly of pickproof means in the nature of auxiliary tumbler pins is not effective with a species of picking technique which combines the picking operation with tapping to recoil the pins of the locking or jamming assembly.

In accordance with my invention, it is an object thereof` to provide a pin tumbler cylinder lock installation which effectively overcomes a species of lock picking technique to jam the cylinder and indicate tampering. By my invention I combine with the known pin tumbler assembly, an auxiliary pin tumbler plug jamming component and locking means therefor which have a spring biased auxiliary driving pin. I further augment the elements of security by combining therewith in the plug and bolt operating means, a lost motion coupling, wherein the auxiliary pin effectively blocks said plug movement before effective engagement between said bolt operated means and plug, to drive an auxiliary driving pin into engagement with an unsupported follower pin before effective engagement between said bolt operating means and the camming means yactuated by said plug.

Still more specifically, it is an object of my invention to overcome a species of lock picking technique by the combination with a pin tumbler `assembly of an auxiliary pin tumbler plug jamming assembly which becomes effective to be driven into engagement with an unsupported follower pin, characterized by a locking driver pin which is spring biased on both its leading and trailing ends to spring bias the locking pin in opposite directions of movement.

Still further, my invention has for its object to provide in a pin tumbler lock, a security feature having an auxiliary driver pin to jam the cylinder plug upon unauthorized endeavors to manipulate the plug by a picking technique, characterized by the incorporation therein of an auxiliary pin tumbler driver and blocking pins to assure entry of such jamming expedient upon unauthorized movement of the key plug.

To attain these objects and such further objects as may appear herein or be hereinafter pointed out, I make reference to the accompanying drawing, forming a part hereof, in which- FIGURE l is a longitudinal fragmentary section of a padlock illustrating my invention;

FIGURE 2 is a magnified section taken on the line 2-2 of FIGURE 1 in the locked position of the padlock;

FIGURE 3 is ya view similar to FIGURE 2, with the padlock bolt turned to the shackle releasing position;

FIGURE 4 is an exploded perspective view of the plug and cam assembly;

FIGURE 5 is a fragmentary section taken on the line 5--5 of FIGURE 3;

FIGURE 6 is a section taken on the line 6-6 of FIG- URE 5 with the key removed;

FIGURE 7 is a view similar to FIGURE 6 with the key plug in a partially angular position;

FIGURE 8 is a view similar to FIGURE 7 with the auxiliary pin in the follower pin driving position;

FIGURE 9 is a section taken on the line 9--9` of FIG- URE S;

FIGURE 10 is a section on the line lll-ltl of FIG- URE 6;

FIGURE 1l is a fragmentary plan view illustrating my invention as applied to a lock cylinder;

FIGURE l2 is a fragmentary section taken on the line 12-12 of FIGURE 11;

FIGURE 13 is a longitudinal fragmentary sectional view illustrating another embodiment of my invention;

FIGURE 14 is a section taken on the line 14-14 of FIGURE 13;

FIGURE l5 is a longitudinal sectional view to illustrate a still further embodiment of my invention;

FIGURE 16 is a fragmentary sectional View taken on the line 16-16 of FIGURE l5;

FIGURE 17 is a fragmentary sectional view of a still further embodiment of my invention;

FIGURE 18 is a section on the line 18--18 of FIG- URE 17.

Making reference to the drawing, I illustrate my iuvention, in one embodiment thereof, in connection with a. padlock 10 having an armored shell 11 closed by a cap 12. The shell and cap are held together by draw pins 13, suitably staked at opposite ends after enclosing a pin tumbler assembly casing 14, and a spring projected shackle l5, the branches 16 and 17 whereof are arranged to be locked by the swinging bolt 18, pivoted on the pin 19- to extend the opposite ends 20 and 21 into corresponding locking slots of the shackle, in a `Well known manner.

The bolt end 2l may be provided with extensions 22 serving as a limiting stop in one direction, and a secondary limiting stop 23 in the opposite direction, whereby in all positions of the shackle, the shackle is held against displacement by the usual shackle spring 24.

The bolt 18 is spring biased into locking position as shown in FIGURE 2 by the spring 25'. The bolt includes a pin 26 which extends adjacent the terminus of the pin tumbler casing and upon movement from the position shown in FIGURE 2 to the position shown in FIGURE 3, is calculated to release the shackle under the biasing influence of the shackle spring 24.

The pin tumbler assembly casing 14 has a plug assembly 28 extended into its plug bearing 27, which plug assembly is held against displacement by the cam plate 29 connected by the usual locking screws for keying engagement with the plug. The cam plate includes a stop lug 30, radially extending therefrom, and a cam 31 axially extending therefrom, having a cam face 32 arranged to move in the path of movement of the bolt pin 2.6 and abut the same.

In the construction as shown, a lost motion coupling exists between the cam face 32 and the bolt pin 26 so that a movement of a relatively large angle is required before the cam face 32 engages the bolt pin Z6, the purpose of which Will appear more lolearly as this description proceeds.

The pin tumbler lock casing previously described has a plurality of pin tumbler bores 33, within which spring lower pins 35. Corresponding lengths of the driver pins and follower pins are illustrated in FIGURE l to show ing a row of primary pin tumbler bores within which are guided spring biased driver pins, a plug bearing in said casing, a key plug mounted for rotation in said plug bearing having complementary bores and having follower pins cooperative with said dn'ver pins for locking said key plug except by predetermined key operation which aligns said driver pins and follower pins along the parting line between said key plug and said casing, bolt operating means carried by said lock, a lost motion coupling between said key plug and said bolt operating means effective to engage and actuate said last named means upon rotary movement of said key plug, an auxiliary pin tumbler plug jamming assembly having `a spring biased auxiliary driver pin on said casing terminating in said plugl bearing, said auxiliary driver pin being coaxially aligned with one of said follower pins when said key plug is displaced a predetermined rotary distance from the locked position thereof, said rotary distance being less than the rotary movement necessary to engage said coupling with said bolt actuator means whereby said auxiliary driver pin effectively blocks said key plug movement before effective engagement between said bolt operating means and said lost motion coupling when said follower pin is aligned with said auxiliary driver pin and said follower pin is unsupported by a key.

2. A pin tumbler cylinder lock in accordance with claim 1 wherein said casing has a spring biased auxiliary driver locking pin transversely guided across the path of said auxiliary driver pin for engaging the trailing end of said auxiliary driver pin to block the same in jamming position when said auxiliary driver pin engages an unsupported follower pin.

3. A pin tumbler cylinder lock in accordance with claim 1 wherein the leading edge of said auxiliary driver pin has a cammed face to accelerate entry engagement with said key plug.

4. A pin tumbler cylinder lock in accordance with claim 1 wherein said casing has a spring biased locking driver pin transversely guided across the path of said auxiliary driver pin for engaging the trailing end of said auxiliary driver pin to block the same in jamming position when said auxiliary driver pin engages an unsupported follower pin, and said auxiliary driver pin is biased at its trailing end by a coil spring, said coil spring in said jamming position of said auxiliary driver pin being projected across Ithe path of said locking driver pin to form a blocking retainer against which said locking driver pin is biased.

5. A padlock including a spring biased bolt to release the shackle thereof, a key operated pin tumbler cylinder for actuating said bolt, said cylinder comprising a casing having a row of primary pin tumbler bores within which are guided spring biased driver pins, a plug bearing in said casing, a key plug mounted for rotation in said plug bear ing having complementary bores and having follower pins cooperating with said driver pins for locking said key plug except by predetermined key operation which aligns said driver pins and follower pins along the parting line between said plug and casing, a cam extending from said key plug having bolt operating means elfective upon rotary movement of said key plug of a predetermined magnitude to engage said bolt, an auxiliary pin tumbler plug jamming assembly having a spring biased auxiliary driver pin on said casing, terminating in said plug bearing, said auxiliary pin being coaxially aligned with one of said 'follower pins when said plug is displaced a predetermined rotary distance from the locked position thereof, said rotary distance being less than the rotary movement necessary to engage said bolt operating means with said bolt whereby said auxiliary driver pin effectively blocks said key plug movement before effective engagement between said bolt operating means and said bolt when said follower pin is aligned with said auxiliary driver pin and said follower pin is unsupported by a key.

References Cited in the tile of this patent UNITED STATES PATENTS 1,707,922 Pepper Apr. 2, 1929 1,755,847 Stevens Apr. 22, 1930 2,137,504 OConnell Nov. 22, 1938 2,222,027 Golden et al. Nov. 19, 1940 2,836,973 Schillizzi June 3, 1958 

